Abstract: A hard disk drive includes a voice coil motor yoke, a base to support the voice coil motor yoke, and formed of a material different from that of the voice coil motor yoke, and a thermal deformation prevention unit which is formed of a material that is substantially the same as that of the voice coil motor yoke, provided between the voice coil motor yoke and the base, and thereby preventing mechanical deformation due to different thermal expansion coefficients between the voice coil motor yoke and the base.

Abstract: A method for making a dual actuator pivot, wherein the need for adhesive bonding is eliminated and assembly time is minimized. An upper sleeve assembly includes an upper and lower ball bearing press fitted therein and a lower sleeve assembly includes an upper ball bearing press fitted therein, the first and second sleeve assemblies being press fitted to a shaft having a ball bearing press fitted at the base of the shaft. A predetermined axial load that is tuned to select a desired resonance frequency for the first and second actuator bearing assemblies may be applied during the press fitting of the first and second sleeve assemblies. The shaft may be chilled to shrink the shaft. Alternatively, the components may be heated.

Abstract: The dynamics of a disk drive actuator are enhanced by redistributing the mass and stiffness of the structure. The two nodal points of the second primary bending mode of the actuator are relocated to positions that are both radially outboard of their original positions. One nodal point is positioned as close to the read-write head as possible at one end of the actuator, and the other nodal point is positioned at the center of the active legs of the VCM coil at the other end of the actuator. This is done to reduce the off-track displacement associated with this fundamental resonance to near zero, allowing higher track densities to be supported.

Abstract: A stepping motor in a thin-sized flexible disk drive is disposed on a pedestal portion in such a manner as to be spaced apart from a main wall of a main plate. The pedestal portion is made of a pedestal and a support metal member. The pedestal is formed by projecting a part of the main plate from a back-surface side thereof to an obverse-surface side thereof. A support plate is screwed to the pedestal to support the stepping motor and to rotatably support the extending end of the rotating shaft of the stepping motor. The pedestal is provided with a plurality of positioning projections formed to project from an obverse-surface side thereof, and a screwing hole for screwing the support metal member. The support metal member is provided with holes formed at positions respectively corresponding to the plurality of projections and the screwing hole.